Cutter head structure with hydraulically operated cutter mountings



Nov. 13, 1951 R. T. MURRAY CUTTER HEAD STRUCTURE WITH HYDRAULICALLY OPERATED CUTTER MOUNTINGS 4 Sheets-Sheet 1 Filed April 2, 1946 7 INVENTOR. I Pusszl/ 7: Murray BY A TTORHE Y Nov. 13,1951 R. T. MURRAY CUTTER HEAD STRUCTURE WITH HYDRAULICALLY OPERATED CUTTER MOUNTINGS Filed April 2, 1946 4 Sheets-Sheet 2 wg rjj r INVENTOR,

Nov. 13, 1951 R. T. MURRAY CUTTER HEAD STRUCTURE WITH HYDRAULICALLY OPERATED CUTTER MOUNTINGS 4 Sheets-Sheet 55 Filed April 2, 1946 km M w w m f l-Hrmu INVENTOR. Pusszz I] T Murray ATTORNEY Nov. 13, 1951 R T MURRAY 2,575,116

CUTTER HEAD STRUCTURE WITH HYDRAULICALLY OPERATED CUTTER MOUNTINGS Filed April 2, 1946 4 Sheets-Sheet 4 I I E R1 FIE EH JNVENTOR. Pussafl 7: Murray ATTORNEY Patented Nov. 13, 1951 'IiIGALLYOPERAT-ED CUTTER MOUNTINGS Claims.

jflI his invention relates generally machin'e's qsuitable-for various meta-1 -machiningoperations.

V .IIn t-hepast certain typesof metalworl :'=in'g ma 1 ,tionary; but where the work is of considerable size it is generally preferable to mount the work stationary and to provide for rotation of the head. Heads of this type which have been available :in the past have not been capable of heavy duty cutting operations, and the degree of accuracy obtained has not always been as high "as is frequently desired. :Inad'dition they havebe'en relatively expensive, particularly witn respeet'to the means employed for feedi'n'g the cutters against the work.

"It isxan object or the present invention to era- Wideia "cutting :d'evice of the above eharacter which "is capable for heavy duty nnfach ining ope? ations'to-alhig hde greeof a in cy.

' .A further object 'oi"'the ion is to ia'iovide "a cutting device tithe-above "cha aeter'wh ch "eliminates conventional conninoatea mechanical motion transmitting mechanism for i'ee'ding the cutters.

Further objects of 'the invention will appear from the fouowi'ns description 11 which the presuch ass gear (not shown) attached to ferried embodiment bf the invention has been "Set forth in detail cofijimetion with the accompanying drawing.

' Referring to the drawing:

Fig. l is a s'ideelvationalview in-section-'il 1ust'r'ating =a cutting device inco'rporatin the pres 'eht invention, and taken along the line 1 at "Fig. 4, v Bi "-2 is a sectional view taken along the line v?2-"2 Figs. *1 and 4.

fl igfis is a sectional view showing themeans To": insuring conjoint movement or the "eyiinders. Fig. 4 is an end view of the cutting ii e, with the portions being removed and portions 'h i h we a v Fig. 5 is a detail view indicated by use E -5 ti *4. v I

Fig. 6 is a sectional detail taken alone the line 5 s of Fig. 4.

A Fig. 7 is a sectional detail taken along-the line 1-40? Fig.1. 7 v p 1 H A Fig. 8 is a sectional detail taken tiltin the line 8 8 of Fig. 1.

, e gns is ajvie'wdiagrammatically' showin suitfl b-1 hydraul -c n c s- FigvQa {shows the reversing valve} in a different position from thatshown in Figt' 9, V

The cutting device illustrated in the drawing consists generally of a head stock 10 which serves to support-and journal the mainbody of the cutting head. The forward 'end'of the assembly carriesthe blocks l2 which serve as mountings tor cutting tools as will be presently described. general the forward :part of the head carries hydraulic meanshaving direct rigid connections with the blocks 12 for :feeding the blocks inwardly during a-cutting operation,;and for returning the same to their outer positions after a cut has been completed. 2

Themain body 'can conveniently be formed of a'number of parts including the stepped "shaft part It and the forward part 14 which is formed to a larger-diameter and which serves to carry the hydraulic means. Suitable bushings l5 and lfiareprovided in the head stock In for journal in? the shaft 13. The shaft [3 can be rotated by the same and driven by suitable means such as electric mhtor and gear reduction; Also autoinatic'or sem'i autoinatic means can be provided foi' controlling the motor to obtain controlled spee as desired. In this connection itmay be ioned that in bperationssuch as the facing er'n gases it i's' desirable to feed the tool inbiiiitin bl l2 "at a constant rate; iircon; inflation with gradual increased driving speed "for the head as the cutters advance inwardly to a sinaller diameter. 7 p I a The j'ournalin of the sharp [3 should be as to arms end play. Thus thrust i'in'gs 20 are shown interposed between the end of the bushin; and an adjacent shoulder on the shaft part 13, a take up adjustment is crevice- 1 by way or threaded col'laifs I"! and 18, Collar l8 can be keyed to 'a hiked adjusted 'po' it A's cofiven'ientineans for attaching x and body p rts 13, I! the shaft provi ed raced end flange [9 which is elaiii'pd to the body part jl'4 by screws 2i "(Figure 2) notveis'tz are 'piovidd fidr accurate relative lbc'ation of trie eparts. To facilitate 'ihanufa'c'ture the spay l4 ts rovided with a separate hub tart Ht,

accommodate the cylindi'block's 21. in Figure 7 ,designated by 36.

3 4 cylinder blocks have been shown in the two P- posed guideways, with two grooves 260: available for additional stationary blocks where it may be desired to carry out outer diameter turning.

Means is provided for interconnecting the cylinder blocks whereby they are constrained to move in unison. Preferably this means makes use of gear racks 28, 29 which cooperate with the pinions 3|. There are two pairs of the racks 23, 29 (Figures 4 and 6) for two opposed cylinder blocks, with the racks 28 being attached to one block by screws 32, and the racks 29 similarly attached to the diametrically opposed cylinder block. Pinions 3! are carried by shafts 33 which in turn are journaled in the body I 4 on a common axis passing through the center of the head as shown in Figure 4. The spacingbetween these pinions corresponds to the spacing between the two pairs of gear racks Because the racks 28, 29 of each pair engage opposite sides of the corresponding pinion 3!, the movement of the two piston blocks must be conjoint or synchronized and in opposite directions, that is either toward or away from each other.

Each cylinder block 21 adjustably carries a corresponding saddle 34 (Figure 6) which in turn serves to mount a cutter mounting block l2. Each saddle is independently guided within the body part 14 and is thus shown provided with flanges 36 which are accurately machined and which are slidably retained within the guideways 31. The flat faces 38, 39 of each cylinder block and saddle 34 are in interface contact, and these parts are retained together by suitable means such as a T slot 4| in the cylinder block, engaged by a retention bolt 42 carried by the saddle. A feed screw 43 is disposed in a bore provided half way in both these parts, With threaded engagement with the saddle. The screw portion 44 of reduced diameter is engaged by a lug 45 on the cylinder block, whereby upon turning the screw by application of a suitable tool or wrench, the corresponding saddle can be adjusted in a radial direction with respect to its associated cylinder block.

'Each cylinder block is provided with a cylinder bore 46, the outer end of which is sealed by the threaded closure 41. A piston 48 is fitted into each cylinder bore and is carried upon the outer end of a rigid piston rod 49. The rod extends through the inner end of the cylinder block and is sealed with respect to the same by suitable means such as the cup washer Closed spaces 52, 53 are thus provided on opposite sides of the pistons for receiving liquid under pressure. The inner ends 54 of the piston rods 49 are shown threaded and rigidly attached to the body part 14a.

A suitable arrangement of ducts and hydraulic connections are provided whereby liquid can be introduced into or permitted to exhaust from either of the two chambers 52, 53. Thus chambers 53 connect with the ducts 56 extending longitudinally through the piston rods 49, which in turn connect with ducts 51 in the body and the common circular duct 58. This system of ducts also connects with ducts 59 and 6!, to the gland or slip ring 52. Chambers 52 similarly connect with the ducts 63 extending through the piston rods, which in turn connect with body duct 54 and circular duct 65. This arrangement likewise connects with ducts similar to ducts 59 and Bi extending longitudinally of the shaft [3 to the slip ring 62. The slip ring end of this duct is Liquid pipes 61, 68 connect 4 with the slip ring 62, and within the ring suitable means is provided whereby pipes 61. 88 connect with the ducts 66, 6|. For example such sealing means can employ cup washers 69, 1| arranged in pairs, and retained apart by spacer rings 12, 13.

Figure 9 diagrammatically illustrates suitable external hydraulic connections to the pipes 61, 68. In this instance the cylinder blocks, pistons and slip ring have been illustrated diagrammatically, to make clear the manner in which pipes 61, 68 are connected to the chambers on opposite sides of the pistons. Pipe 61 which connects to the outer chambers 52 also connects to a suitable new control valve or variable orifice 16, which in turn connects by pipe 610: to the reversing valve 11. Pipe 68 connects to a counterbalance valve 18, which in turn likewise connects by pipe 68a to reversing valve 11. Valve 18 is shunted by the check valve 19. Reversing valve 11 has a discharge pipe 8| leading to the auxiliary liquid reservoir 82, and this reservoir connects to the inlet side of pump 33,v which discharges through pipe 84 to the reversing valve 11. Reversing valve 11 is such that in one operating position, pipes 81 and 84 connect respectively to the pipes 68a and 6111. However, for the other operating position pipe 8! is connected to the pipe 61a and pipe 84 to the pipe 68a.

The purpose of the counterbalance valve 18 is to provide a predetermined amount of pressure in chambers 53 while liquid is being introduced into the chambers 53 to force the cylinder blocks and cutters inwardly. Thus in its construction and mode of operation it is similar to a back pressure regulator. For the other operating position of valve 11 the connections are reversed, that is the pump connects with the counterbalance valve 18 and the check valve 19, and the discharge pipe 81 connects with the fiow'control valve 15; Upon back flow through pipes 81 and 68a check valve 19 opens whereby liquid' is exhausted'from chambers 53 and liquid under pressure introduced into chambers52. Valve 11 is-preferably con trolled automatically by a suitable timing cam,

whereby the cylinder blocks are caused'to move inwardly while the cutters are 'taking'a cut, and whereby after the desired out "has been taken, the cylinder blocks and cutters are more rapidly re turned to their outer positions to permit removal of the work. Flow control valve 16 is set at a suitable value to provide back pressure in chamber 52 while liquid is being introduced into chamber 53.

Operation of the complete machine can now be reviewed as follows: The work 86 to be operated upon, which may be provided with an end flange 81 to be faced upon opposite 'sides, is clamped upon a suitable table (not shown) of the machine. The head stock I 0 is positioned on the frame or bed of the machine in such amanner that the forward end of the head is in suitable position for operating upon the work. 'If desired the attachment to thebed of-the machine may be to a suitable carriage or like means whereby the position of the head can beadiusted in different directions relative to the work. Suitable cutters 88, 89 are secured to the tool mountings l2, and are adjusted in accordance with the cuts required. Assuming that one desires to carry out turning on a fixed diameter prior to -a facing operation, stationary blocks and cutters are mounted in the grooves 26a. Assuming that the cylinder blocks are in their outermost positions, whereby the cutters 88, 89 are retracted from the work, a cutting cycle is started by commencing rotation of the head and advancing the head stock Ill to complete an outer turning operation. The reversing valve 71 is then positioned whereby liquid under pressure is applied to the chambers 53, to feed the cylinder blocks and thus the cutter mountings i2 inwardly at a controlled constant rate. The liquid in chambers 52 is displaced through the control valve 76, and ultimately by pipe 8| to the storage reservoir 82. Liquid from pump 83 being supplied to the chambers 53 can be regulated by adjusting the control valve 16, thereby regulating the rate of movement of the cutters. With the set-up of cutters illustrated in Figure 1, a double out can be taken upon both the forward and rear faces of the flange 81. When the cuts have been completed the timing or cycling means employed reverses the positioning of valve 11 to that shown in Figure 9a, with the result that p p 83 now supplies liquid through control valve 16 to chambers 52, while at the same time liquid in chambers 53 is displaced and returned through check valve 19 to the reservoir 82. Movements of the cutters to initial outer positions can be relatively rapid compared to the rate of feed. In Figure 9 the cylinders are shown near the end of the inward feed and prior to changing the reversing valve 11 for retraction of the cutters.

Maintaining a substantial back pressure in chambers 52 while liquid is applied to chambers 53 for feeding the cylinder blocks inwardly, serves to insure positive even feed of the cutters under heavy duty cutting operations, without possibility of chatter. The cutter mountings l2 are capable of withstanding relatively heavy thrusts while taking a out, due particularly to the fact that they are individually retained within adequate guideways. The cylinder blocks are likewise capable of imparting the type of positive steady feed desired because they are directly and rigidly attached to the saddles, and also because the pistons and associated piston rods are stationary and are rigidly attached to the body of the head.

In setting up the machine it will be evident that the feed screws 43 can be adjusted to vary the positioning of the saddle 34 with respect to the cylinder blocks as desired.

I claim:

1. In a metal working machine, a head structure adapted to be rotated, radially extending guideways formed on the head, cutter mounting means carried by said guideways, means including a pair of hydraulically operated cylinder and piston units for moving said mounting means, the pistons of said units being rigidly attached to the head and the cylinders of said units being rigidly and directly attached to said mounting means, and means including a pair of racks and a cooperating pinion for synchronizing movements of said mounting means.

2. In a metal working machine, a body structure adapted to be rotated, a pair of radially extending guideways formed on the body, a pair of cutter mounting saddles carried by said guideways and adapted to move radially along the same, a pair of hydraulically operated cylinder and piston units, the cylinders of said units being directly and rigidly attached to said saddles and the pistons of said units being rigidly attached to a central portion of the body, two pairs of gear racks attached to the cylinder and extending along paths located on opposite sides of the center of rotation of the head, and pinions jpurnaled upon'the body and engaging the racks of said pairs, whereby movements of the saddles in a radial direction are synchronized. Y

3. In a metal working machine, a head structure adapted to be rotated, a pair of radially extending guideways formed on the head, a pair of cutteimounting means each carried by a guideway, means including two pairs of hydraulically operated cylinder and piston parts for moving said mounting means, one of said parts of each pairbeing directly and rigidly attached to the mounting means, the axis of each pair extending adjacent to and parallel to its associated guidewayfand means for synchronizing movements of the mounting means.

4. In a metal working machine, a head structure adapted to be rotated, a pair of radially extending guideways formed on the head, a pair of tool mounting means carried by said guideways, means including two pairs of hydraulically operated cylinder and piston parts for moving said mounting means, said piston part of each pair being rigidly attached to the head and said cylinder part being rigidly attached to the associated mounting means, each of said cylinder and piston parts being in close proximity with and extending 1' parallel to the associated guideway, and means for synchronizing movements of the mounting means.

5; In a metal working machine, a head structure adapted to be rotated, a rotatable shaft to which the head is attached, a radially extending guideway formed on the head, a cutter mounting means slidably carried by the guideway, hydraulic operating means for said cutter mounting means comprising interfitting cylinder and piston parts carried by the head adjacent to and parallel to the guideway, said parts being formed to provide closed fluid chambers on both sides of the piston to thereby provide a double acting hyraulic operating means, said shaft being provided with ducts communicating with both said chambers for efi'ecting hydraulic movement of said mounting means in either one of two directions.

RUSSELL T. MURRAY.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 632,230 Berger Sept. 5, 1889 1,146,193 Miller July 13, 1915 1,449,463 Van Hamerveld Mar. 27, 1923 1,454,121 Lavoie May 8, 1923 1,814,675 Erickson Oct. 24, 1930 1,986,862 Svenson June 8, 1935 2,383,050 Esson June 9, 1943 2,340,513 Deuring Feb. 1, 1944 FOREIGN PATENTS Number Country Date 2,526 Great Britain 1853 

